Experiments are proposed to study ligand diffusion in proteins. We will extend studies of xenon, myoglobin using new ligands. Work on a novel nanosecond circular dichroism instrument will proceed. It will be used to examine carbon monoxide photolysis in myoglobin and hemoglobin. We also suggest studies of protein folding based on the use of spin labels to learn about the structure of kinetic intermediates and the use of specific amino acid substitutions to study kinetic mechanisms. Finally, a set of experiments is devoted to the way solvent alters protein and peptide conformation.